Solve by factoring

a^2 -121 = 0

(a+11)(a-11) = 0

a = -11
a = +11

To solve the equation a^2 - 121 = 0 by factoring, we first need to recognize that it is a difference of squares.

The equation can be rewritten as (a - 11)(a + 11) = 0.

Now we set each factor equal to zero:
a - 11 = 0 or a + 11 = 0.

Solving these equations, we find that a = 11 or a = -11.

Therefore, the solutions to the equation a^2 - 121 = 0 are a = 11 or a = -11.

To solve the equation a^2 - 121 = 0 by factoring, we need to rewrite the equation in the form (a - b)(a + b) = 0, where a and b are some expressions.

First, we can rewrite 121 as 11^2 since 11 multiplied by itself gives 121.

So, we have a^2 - 11^2 = 0.

Next, we can recognize that this equation follows the difference of squares pattern, which states that a^2 - b^2 can be factored as (a - b)(a + b).

In this case, a^2 - 11^2 can be factored as (a - 11)(a + 11) = 0.

Now, we set each factor equal to zero and solve for a:

a - 11 = 0
a = 11

a + 11 = 0
a = -11

Therefore, the solutions to the equation a^2 - 121 = 0 are a = 11 and a = -11.